6mm Dasher,Finally Completed)

[Skeeter]

Finally completed my Dasher after 2 years of work. Here are the specs

Browning B78 Falling Block,blue printed, accurized and case hardened by Doug Turnbull)
Krieger Custom,1 of 1) Octagon Bull Barrel,1:10 twist, 1.25" at action tapered to .980",5") from action, then straight no taper to brake).. overall length 26"
KDF Custom Muzzle Brake,contoured to octagon barrel)
Custom,2lb) 2-stage trigger worked to fit Browning Action
Badger mounts & Kelby Rings
Leupold VX-III 8.5-25x 50mm w/30mm tube w/varmint reticle
PT&G Dasher reamers .269, Custom Dasher FL Sizing, Comp. Neck and Comp. Seating Dies

A couple of questions.

1.) I now need to fire form my brass and have purchased 300 rounds of Lapua 6BR with .271 neck diam. Is it better for me to size up to say .257 then neck down to say .267 creating a false shoulder to keep the bullet form moving during fire, or just neck turn the .271 necks down to .267 and use that instead?

2.) I don't have easy access to a range, so I was thinking of going the Cream of Wheat method for initial fire forming instead of full loads. If I use a 10% load, then fill with COW, top off with sizing wax, would it be too violent to discharge in my basement?

3.) What do you think of using a 95gr Berger VLD in a 1:10 twist barrel?

All fire forming will be done in a surrogate Sako barrel reamed with same reamers as finished Krieger.

Thanks for your assistance

 

[Forum Boss]

Skeeter,

I've been wanting to do a story on a falling block action for quite some time -- please keep notes on this gun and take photos. Perhaps we can do a story.

False shoulder method seems the most foolproof with this cartridge. If you use the right procedures, loss of about 1 case per hundred is typical. You can turn the case neck part-way,elegant solution) -- but you have to hit the length of turn section DEAD ON for every case.

Accuracy should be good enough during fire-forming that I'd just go ahead and shoot the gun with the good barrel. Enjoy it.

If you're really, really trying to safeguard the life of that Krieger than go ahead and use fire-forming barrel. My point is that you might enjoying the fireforming process and be able to do some accuracy work.

10% load won't blow the shoulder forward successfully. Not a good idea.

Some people have gotten the 95 Berger VLD to work in a 10-Twist barrel but there's a good chance it WON'T stabilize. Berger recommends a 1:9". Bottom line, in a 10-twist it might work, then it might not. As the bullet slows down with distance it will also become less stable. So it might work at 200, not at 500 yards.

 

[Skeeter]

Thank you Editor in Chief for the quick reply.

I will definitely keep you up to date on my load progress.

I decided on the surrogate barrel since this is going to be a varmint gun and forming 300-400 pieces of brass seemed like more work then what I wanted to deal with to break in the expensive Krieger barrel,not to mention all the cleaning in between groups). The smith only charged me $200 for the Sako, reamed and installed for forming the brass.

So you don't think COW method is a good idea?

If the 95 VLD's don't stabilize, what recommendations can you give me on other bullets to try?

Also, I would be honored for you to do a story on my Browning once I have it all worked out. Thank you.

Mark

 

[Forum Boss]

Cream of Wheat method should work. You just need more powder. Some guys use a pistol powder, but I Can't give you specifics on that... you have to ask the Dasher guys. Richard Schatz knows as much as anyone. He often posts on this board.

Sierra 95 was designed to work in a 10-twist. So that SHOULD be an option.

FYI, our story on the Savage 6BR Striker showed the Berger 95 VLD to work in that 10-twist gun--no signs of keyholing. But you won't know with your rifle 'till you test.

Berger 80 is an excellent bullet--very accurate.

Scenar 90 is a very good bullet that should work in a 10 twist. But not sure if it will give the effect on critters you want.

Many guys like the 87gr V-Max. I think it has an odd profile and it wasn't near as accurate as Berger 80s for me, but you can try it.

There is also the Berger 88 lodrag. Unusual bullet design. It has shot well for some guys, but I think it takes some tuning.

I'd start with the Berger 80s out to 250, then try the 95s and see if they work for longer range.

 

[Skeeter]

Thanks again for the advise. I will try the Berger 80's and get back to you on them.

Any advise on a starting load to fire form? I have several different powers I can use since I already reload for 220 Swift, 22-250, 6mm Rem and about 5 pistol cartridges and shot shell.

These are the powders I have:

Fast Burning
N310
Titewad
Bullseye
Red Dot
Clays
N320
WST
WSL
Unique
E3

Slow Burning
H4198
H322
IMR4895
RL15
H380
RL19

Thanks again

 

[Tim_in_TN]

Skeeter, I recenly fireformed 150 cases in a dedicated barrel. I went to this page and picked out a load that appeared to be giving top speeds, and higher pressure to help out the process.

http://www.6mmbr.citymaker.com/varmintloads.html

I chose the load I believe the 4th using the 58 grain bullet and 2230.

My smith suggested what may be the best idea ever, to coat the brass with Lee case lube pryor to shooting them. It is some really slick stuff, that helps the brass flow into the new shape.

Let it dry and buff it off with a clean rag, load them and shoot.

I bumped the load 1/2 grain to 33 because of all the movement of the brass, and it worked out nicely.

 

[SongdogHunter]

I have 2 Browning B-78 one is a 20 Bobcat and one will be getting a new barrel in a .257 x 47 AI Lapua here shortly.

Gotta love the single shots.

SDH

 

[Forum Boss]

I would not suggest using a FULL load AND case lube when making Dasher cases in a falling block rifle.

I would also be cautious about using what we list as "max bolt gun loads" in that B-78.

Browning Falling Block

I have a friend who fireforms 22 PPCs with lubed cases. Even in a bolt gun, he backs off his load to 22 grains rather his normal 27 grains of Benchmark, so that give you some idea of charge reduction. The shoulder won't fully "sharpen up" on this load, but it's close.

In theory, the lube can help form the case without excessive stretch at the back end of the case. I'm note sure how much the lube really helps, but some guys think it does. However, lubed cases can also increase bolt thrust and this is something to be mindful about with any falling block.

 

[Skeeter]

Thanks everyone for the great advice.

I'm currently waiting on a primer pocket uniformer and flash hole deburring tool to arrive, as soon as they get here,should be tomorrow) I will start prepping the cases. Since I shoot about 400 rounds in about 3 days of varmint hunting, I'll have to prep all 400 cases at once, which will probably take me all weekend. I'm planning on creating a false shoulder and full BR load to fire form. I think I'll go with the following to form and check a few before doing them all.

Neck size up with .257 Hornady mandrel
Neck size down with bushing .267 O.D. to new shoulder length
30gr of H4895, CCI450 primer, Combined Tech 55gr BT
Seat bullet into the lands and fire.

I'll check for pressure and shoulder angle to ensure it's moving the brass to the appropriate angle.

I will consider this stage the first fire forming and will do a second fire form using a full dasher load and appropriate bullet to ensure sharp shoulder angles and appropriate length.

I'll take some pictures as I go. Thanks again.

 

[Forum Boss]

I wouldn't bother to uniform the primer pockets. Truly. Re the Flash holes -- inspect them and decide what to do. Personally, I would not ream them, but I would remove any obstructions or flakes of brass you see in the flash holes.

Check the Bulletin re recent Lapua Brass. You can use an inexpensive pin vise to knock out any little brass flakes that are blocking the flash-hole.

INFO: http://accurateshooter.wordpress.com/2007/03/30/brppc-flash-hole-deburring-tips/

 

[alf]

Skeeter,
I think you're heading for trouble.
Your chamber neck diminsion is .269. Even using a .267 bushing, with spring back it will probably measure .268. After you seat the bullet, you'll be up to .270.
Too bad your fire form barrel doesn't have a no-turn neck. It would eliminate this headache.
I can only see one of two options.
Fire form with cream-of-wheat and a wax plug, or turn your necks to where the neck/shoulder juncture will be, then load and fire form.

Al

 

[Skeeter]

Darn, I need to post here before I shop:, Thanks again for the info... I will definitely go the route of inspection and removal instead of just reaming out the flash holes. I do have a pin vice and #53 bit... one question, do you do it from the bottom of the case or the inside?

 

[Skeeter]

Hi Al,

Thanks for the reply.

I was figuring at first I would do the COW method, but seemed like necking would resolve the diam. issues.

If not, I kinda like the COW route as I can do it in my basement and that should at least get me the initial shoulder blown forward and the angle started. I could then do a second fire form, but this time neck turn the brass before loading which will uniform the necks and resolve the .269 dilemma and use a full dasher load instead.

Does this seem like a good idea? Thanks

 

[alf]

NO, it's not a good idea.
You're gonna have a .270 loaded round.
Ain't gonna fit in a .269 chamber.
If you do get one in, I wouldn't want to be the one pulling the trigger.

Al.

 

[Skeeter]

I just took one of my Lapua Brass and took measurements with my mic. The brass measured O.D. .270, with neck case thickness of .012.

I chamfered the mouth and ran it through my 6BR neck die and necked it down to .267 and loaded a Berger VLD 95 into it. Case diameter measures exactly .268 loaded... which is exactly what I thought it would be since the bullet's diameter is .243,+).024 for the case thickness and bounce back.

These rounds load into my chamber no problem. If they do bounce back to .268 after fire forming, I can always neck them back down to .267 before my next reload.

 

[Skeeter]

Okay, I spent the day yesterday working on my brass. I got 400 rounds ready to fire form. Here is what I did.

1.) Inside/outside chamfered all case mouths.
2.) Used a # 53 dill bit on all primer pockets to remove any burs
3.) Ran all brass through my Redding 6BR Type-S bushing die. I removed the Redding expander and replaced it with a Hornady .257 mandrel expandron. I used a .282 Ti bushing and ran all brass to expand the necks.
4.) I got a No-Go and Go-Gauge from Daivd Kiff when he made my reamers so I measured off the Go-Gauge to determine shoulder placement. Reduced it on my Redding Comp. die by .005 and worked my way down until a very firm action close.
5.) I then placed a .267 Ti bushing into the die and ran all brass through it. Brass seats with a firm close of the action and minimal extractor marring.

What I would like to do today is fire form them using the Cream of Wheat method since I have a large basement to shoot in and weather is bad outside. Below are the powders I have to work with. All are fast burning pistol powders, but would like some advise on a starting load for fire forming my Dasher. I also have small pistol primers,CCI 500) to use instead of small rifle.

These are the powders I have to use.
N310
Titewad
Bullseye
Red Dot
Hodgen Clays
WST
WSL
Unique
WSF

Thanks again for any advise.

 

[Forum Boss]

Skeeter,

Sounds like you're on track. Hopefully some guys can give you specific powder advice -- as to how much pistol powder to use. Be sure to shot the CW into an area where it won't cause a lot of mess,DON'T use a bucket placed close to the barrel.) And be sure to use eye protection.

BTW, if you have a larger version of the above picture--could you send it along,without the labels). I'd like to use it on our 6BR Improved page. It would also make a good bulletin item if this system works out for you.

Thanks!

 

[Skeeter]

I started fire forming the brass today. I started with a modest 4.0 grains of Titewad to see how the pressure would look. The charge only bumped it out marginally. So I kept moving the weight up in .3 gr increments until I hit a point where I think the shoulder and neck are close,although not perfect). I think if I bump the weight up another .5 gr it might flatten out the shoulder angle a little bit more, but realistically the shoulder angle will flatten itself out completely when I do the full fire form with a bullet.

As for the process... a lot of work mixing powder, paper, COW, paper and shoot. Although nice to be able to shoot in the basement. Although, not as loud as a full 6BR round, was about the equivalent of my 9mm XD.

Here are some results.

 

[Forum Boss]

Skeeter,

That's a GREAT photo. I'm glad you worked in increments as now everybody can see how the shoulder "rounds out" and moves forward with pressure.

Please, if you can, save your "partly formed cases" at 5.0, 6.0, 6.5. These are VERY useful to illustrate the process. Looking at what you've got... I'd be tempted to go straight to 8 grains or more.

Wearing my Editor's hat it would be great if you could continue to work up in 0.5 or 1.0 gr increments and take pix so we could have more case examples in the series. This is really interesting stuff!

 

[Skeeter]

Thanks... I will certainly save all the brass as I work up in .5 gr increments. I plan on taking it up to about 8.5 gr as I worked up to 7.5 gr last night and although the shoulder is flattening out, there is still a small portion that is a little round. Also, zero signs of pressure so far.

I will post another photo with all the increments as soon as I hit the magic number of grains.

,I'll also PM you a larger picture as well)

Thanks again,

Skeeter